//----------------------------------------------------------------------------//
//                                                                            //
// ozz-animation is hosted at http://github.com/guillaumeblanc/ozz-animation  //
// and distributed under the MIT License (MIT).                               //
//                                                                            //
// Copyright (c) Guillaume Blanc                                              //
//                                                                            //
// Permission is hereby granted, free of charge, to any person obtaining a    //
// copy of this software and associated documentation files (the "Software"), //
// to deal in the Software without restriction, including without limitation  //
// the rights to use, copy, modify, merge, publish, distribute, sublicense,   //
// and/or sell copies of the Software, and to permit persons to whom the      //
// Software is furnished to do so, subject to the following conditions:       //
//                                                                            //
// The above copyright notice and this permission notice shall be included in //
// all copies or substantial portions of the Software.                        //
//                                                                            //
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR //
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,   //
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL    //
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER //
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING    //
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER        //
// DEALINGS IN THE SOFTWARE.                                                  //
//                                                                            //
//----------------------------------------------------------------------------//

#include "SkrAnimTool/ozz/track_optimizer.h"

#include <cassert>
#include <cstddef>

// Internal include file
#define OZZ_INCLUDE_PRIVATE_HEADER // Allows to include private headers.
#include "decimate.h"
#include "SkrAnimTool/ozz/raw_track.h"
#include "SkrAnim/ozz/base/maths/math_ex.h"
// Needs runtime track to access TrackPolicy.
#include "SkrAnim/ozz/track.h"

namespace ozz
{
namespace animation
{
namespace offline
{

namespace
{

template <typename _KeyFrame>
struct Adapter {
    typedef typename _KeyFrame::ValueType                        ValueType;
    typedef typename animation::internal::TrackPolicy<ValueType> Policy;

    bool Decimable(const _KeyFrame& _key) const
    {
        // RawTrackInterpolation::kStep keyframes aren't optimized, as steps can't
        // be interpolated.
        return _key.interpolation != RawTrackInterpolation::kStep;
    }

    _KeyFrame Lerp(const _KeyFrame& _left, const _KeyFrame& _right, const _KeyFrame& _ref) const
    {
        assert(Decimable(_ref));
        const float alpha =
            (_ref.ratio - _left.ratio) / (_right.ratio - _left.ratio);
        assert(alpha >= 0.f && alpha <= 1.f);
        const _KeyFrame key = { _ref.interpolation, _ref.ratio,
                                Policy::Lerp(_left.value, _right.value, alpha) };
        return key;
    }

    float Distance(const ValueType& _a, const ValueType& _b) const
    {
        return Policy::Distance(_a, _b);
    }

    inline static ValueType identity() { return Policy::identity(); }
};

template <typename _Track>
inline bool Optimize(float _tolerance, const _Track& _input, _Track* _output)
{
    if (!_output)
    {
        return false;
    }

    if (&_input == _output)
    {
        return false;
    }

    // Reset output animation to default.
    *_output = _Track();

    // Validate animation.
    if (!_input.Validate())
    {
        return false;
    }

    // Copy name
    _output->name = _input.name;

    // Optimizes.
    const Adapter<typename _Track::Keyframe> adapter;
    _output->keyframes = Decimate(_input.keyframes, adapter, _tolerance);

    // Output animation is always valid though.
    return _output->Validate();
}
} // namespace

bool TrackOptimizer::operator()(const RawFloatTrack& _input, RawFloatTrack* _output) const
{
    return Optimize(tolerance, _input, _output);
}
bool TrackOptimizer::operator()(const RawFloat2Track& _input, RawFloat2Track* _output) const
{
    return Optimize(tolerance, _input, _output);
}
bool TrackOptimizer::operator()(const RawFloat3Track& _input, RawFloat3Track* _output) const
{
    return Optimize(tolerance, _input, _output);
}
bool TrackOptimizer::operator()(const RawFloat4Track& _input, RawFloat4Track* _output) const
{
    return Optimize(tolerance, _input, _output);
}
bool TrackOptimizer::operator()(const RawQuaternionTrack& _input, RawQuaternionTrack* _output) const
{
    return Optimize(1.f - std::cos(.5f * tolerance), _input, _output);
}
} // namespace offline
} // namespace animation
} // namespace ozz
